Title:
Educational device
Document Type and Number:
United States Patent 3166856

Inventors:
Uttal, William R.
Publication Date:
01/26/1965
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Assignee:
IBM
Primary Class:
434/229
International Classes:
G09B13/00
US Patent References:
1984599Educational device
2613453Training typewriter
2783454Data assembly apparatus
2970386Arithmetic instructing aid circuit
3021937Selective interlock mechanism
3103073Instructor system
Foreign References:
DE153527C
GB762367A




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